Shock-absorber.



E. FLENTJE.

SHOCK ABSORBBR.

AYPLIOATION FILED 001.29, 1909.

Patented J al1. 2, 1912.

/H///M l.

UNITED STATES,A PATENT OFFICE.

ERNST FLENTJE, 0F C'AMBRIDGE, MASSACHUSETTS.

SHOCK-ABSORBER.

'Specicationvof Letters Patent.

Application led October 29, 1909. Serial o. 525,285. f

To all whom t may concern.'

Be it known that I, ERNST FLENTJE, a citizen of the United States,residing at Cambridge, county of Middlesex, and State of .Massachusetts,have invented an Improve- -ment in Shock-Absorbers, of which thefollowing description, in connection with the accompanying drawing, is aspecification,

like characters on the drawing representing like parts. Y

This invention relates to shock absorbers for automobiles and similarvehicles, and is in the nat-ure of an improvement-on the device shown inmy Patent No. 899,662, dated September 29, 1908. The device shown insaid patent comprises a cylinder adapted to contain liquid and a portedpiston therein which is provided with valves to control the ports scthat `Vthe liquid in the cylinder will act to retard the movement of thepiston and thus check the recoil of the spring.

In my present invention I have improved the device shown in my formerpatent by providing a cushion device which will check the openingmovement of the valves of the ported piston and will prevent anyclicking noise incident to `such opening movement.

The invention also improves hangers in other ways, all as more fullyhereinafter` described and then pointed out in theappended claims.

Referring to the drawings wherein I have shown one embodiment of theinvention, Figure 1 is a sectional view of my improved shock absorbertaken in a vertical plane at right angles to the axis of the automobile;Fig. 2 is a sectional view vtaken in a plane at right angles to that ofFig. 1; Fig. 3 is a top plan view of the piston; Fig. 4 is a bottom planview of the piston.

generally used, I have not deemed it necessary to illustrate theautomobile and have confined the drawings to the parts of the automobileto which the shock absorber is directely attached.

3 indicates a portion of the side sill of the automobile body and 4indicates the axle. The cylinder of the shock absorber is shown at 5,and it contains a piston 6 which is provided with two sets of ports 7and 8, the ports 7 being larger than the ports 8. A valve 9 is employedto close the larger ports 7 when the plston moves upwardly, and thisvalve has secured thereto two U-shaped members 10 that pass down throughthe ports 7 and serve to limit the upward move-v ment of the valve, allas shown in my abovementioned patent. The cylinder 5 has secured theretoa head-11 which carries at one side an eye 12 to which the hangerconnected to the axle is secured. The piston-rod 13 has secured to itsupper end a collar 14 provided with a laterally-extending arm 15 whichterminates in an eye 16 to which is connected the hanger that is securedto the side sill 3. These two hangers are shown at 17 -and 18respectively, and they may be of any suitable construction, although Iprefer to make them with screw-threaded stems which are screw-threadedto bracketsv 19 and 2O that are secured to the sill 3 and axle 4respectively, all as shown in my co-pending application Se. No. 519,776,led September 27, 1909.

By `forming the eye 12 on the side of the cylinder 5, instead of on theend thereof, as in my former patent, and by making the eye 16 for thehanger 17 at the end of the laterally-extending arm 15 instead of on theend of the piston-rod, I am able to produce -a shock absorber which hasthe same amount of movement as that illustrated-in my former patent, butwhich has a considerably less over-all length. This is a decidedadvantage because in many automobiles the space in which a shockabsorber can be located is so limited that it is diiicult to apply ashock absorber of the type shown in my former patent.

In the operation of the device as shown the lifting of the valve 9 whenthe piston begins to descend is comparatively rapid and 'with theconstruct-ion such as shown in my above-mentioned patent, the impact ofthe loops or U-shaped members 10 against the under side of the pistonwhen the valve opens will make an objectionable clicking noise. In orderto avoid this, I have placed springs or cushioning devices 32 aroundeach of the U-shaped members, these cushioning devices acting to cushionthe movement of -the valve and prevent any objectionable noise. V

I have hereinv shown the piston rod 13 as in the form of a tube which isopen to the cylinder below the piston and which is pro- .vided withports 21 which open into the cylinder above the piston.

y Situated within the piston-rod is a valve or plunger 22 which extendsthe Vlength thereof and which has' screw-threaded en- Pa'tent'ed Jan.2,1912.

gagement with the interior of the piston-rod at its upper'end, as at 23.The end 24 of the v more freely from'the upper to the lower end valve 22projects beyond the piston-rod and is made square so that a wrench may be applied thereto. The v alve 22 is of such a length that by' turning itin the piston-rod, the lower end thereof will diminish or increase thesize of the ports 21thus varying the resistance developed by the shockabsorber. If the vspring of the automobile is a stiff one anda shockabsorber having a 'considerable resistance is required, the valve 22will be screwed down so as to nearly or entirely close the ports 21, andwhen the piston rises, therefore, the liquid can only pass through theports 8. If, however, the automobile /is heavily loaded or the spring is4'such as to require a shock absorber having a comparatively slightresistance, the valve 22 will be unscrewed to increase the area of theports 2 1, in which case the liquid will flow ofthe cylinder and a lessresistance will be developed in the shook absorber. Since the valve 22is accessible through the top of the piston-rod and through the top; ofthe hanger, it will be obvlous that said valve may be easily adjustedtoregulate the resistancel of the shock absorber without removing theshock absorber from the vehicle.

The piston-rod 13 passes up through a stuiing-box 25 which is providedwith packing 26'a's usual. I have found that with the stufing-box asordinarily constructed the packing. needs to be tightened every once ina while in order to 'prevent any leakage.

lThe average chauffeur, however, 1s very likely to neglectA to keep thestutling-box tight and if the/liquid leaks out, the shock absorber willnot act properly. I have-provided herein a stuffing-box which willautomatically keep the packing tight and pre- A vent leakage, and Iaccomplish this by elonating the neck of the stuiiing-box and placingtherein a spring 27 which-bears on the packing. The lower coil of thisspring is provided with a. tapered or 'beveled face 28, as seen best inFig. 1,-and the upper end of the spring is secured to a a ed bushing 29that fits within the spring an bears against the capBO vof thestuffing-box. The spring p27 acts to apply pressure continuously to thepacking and the bevel face 28 acts to crowd the packing around thepiston'- rod, thus veffectively preventing any leakage.

It sometimes occurs that an automobile spring` will havea violentrecoilduring whichl thel .piston is drawn up to the top of the cylinder.Y In order to avoid the danger of the piston striking the top ofthecylinder during such violent reco11 I propose to so place the ports 2lthat they will be drawn into the stuiing box before the piston reachesthe upper limit of its movement, as shown in Fig. 2. It will thus beseen that if there is a violent recoil and the piston moves clear to theupper end of the cylinder, the ports 21- will'be closed by entering thestuffing-box before the piston strikes the upper end of the cylinder,and thus the latter part of the movement lof' the piston will becushioned and the piston will be prevented from striking the end of thecylinder.

I have also shown a shield or cover 34l which surroun'ds the piston-rodand extends from the cap 30 of the stufling box to the collar 14 of theupper hanger and which serves to prevent any-dust lor other foreignsubstance from being drawn into the stuingbox and through thestuiing-box into the cylinder by the movement-of the piston-rod. Thiscover or shield 34 is in the nature of a flexible tube whichis connectedat one end to the cap 30 and at the other end tothe col-k lar 14. Inorder to connect the cover to the cap and collar I havepr'ovidedeachwith an undercut annular shoulder 35 over which the `end of the cover 34is placed and have connected the cover tothe shoulders by wires or cords36. .A spring 437 situated within the cover and Surrounding thepiston-rod prevents the cover from contacting with the piston-rod andbeing worn thereby.

`Having fully described my invention, what I claim -as new and desire tosecure by Letters Patent is N f 1. In a shock absorber, the combinationwith a cylinder to contain liquid, of a piston therein, said pist-on,having a plurality of ports, a valve for said ports situated above thepiston, a'U-shap'ed member secured to the valve and extending throughthe ports beneath the piston for limiting the upward movement yof thevalve, and a cushioning device on the-U-shaped member.-

2. In a shock absorber, the combination with a cylinder to containliquid, of a piston therein, said piston having a plurality of ports, avalve for said ports situated above the piston, a .U-Shaped membersecured to the valve and extending through the ports beneath the pistonfor limit-ing the upward movement of the valve, and a coiled springsurrounding the U-shaped member and operating to cushion its movement.

In testimony whereof, I have signed my name to this specication, inthe'presence of two subscribing witnesses.

v ERNST FLENTJE.

Witnesses:

-Louis C. SMITH,

THOMAS J. DRUMMQND.

